diff --git a/index.js b/index.js
index 6d0c712..ec6a8a5 100644
--- a/index.js
+++ b/index.js
@@ -19,8 +19,9 @@ const isUnsafeKey = key => {
 
 const validateKey = key => {
   if (typeof key !== 'string' && typeof key !== 'number') {
-    key = String(key)
+    key = String(key);
   }
+
   if (isUnsafeKey(key)) {
     throw new Error(`Cannot set unsafe key: "${key}"`);
   }